CAN
LUTRON DIMMERS BE GANGED ?Yes. When 2 or more dimmers are in the same wallbox, they are considered
"ganged". To install ganged dimmers, simply remove the dimmer side sections
from the heat sink. The maximum wattage capacity for each dimmer is reduced
(derated) so that the dimmer does not overheat.
See also Ganging and Derating

QUIET
OR FULLY VARIABLE FAN CONTROLS, WHAT'S THE RIGHT CHOICE ?Quiet Fan Control- If the application is one ceiling paddle fan, a quiet
(step) fan control is the best choice. Quiet fan-speed controls will not cause
fan-motor hum, making them ideal for bedrooms, children's rooms, media rooms,
and other locations where noise is particularly important.

Fully Variable Fan Control Although fully variable (full range)
fan-speed controls are an option for controlling one single ceiling paddle fan,
they are the only choice for controlling more than one ceiling paddle fan,
bathroom, whole-house/attic, range hood, agricultural fans and heat exchangers.

DOES
DIMMING AFFECT HALOGEN LAMP LIFE ?
Yes, dimming increases incandescent lamp life. Halogen lamps are incandescent
lamps with a tungsten filament. Lutron's pilot test data suggests that halogen
lamps will have an expected lamp life similar to other incandescent lamps when
dimmed. As an example, one type of halogen lamp with a rated life of 2000 hours
dimmed to 80 volts has a life extension of at least 5 times. Lutron is
continuing testing with various halogen lamps.

WHY DO DIMMERS GET WARM, AND IS THIS SAFE?The technical explanation. During normal operation, solid-state dimmers
generate heat. A solid-state dimmer is roughly 98% efficient-2% of the power is
dissipates as heat, causing the dimmer to feel warm to the touch. The closer a
dimmer is run to full output and the higher the load (watts) on the dimmer, the
warmer it will feel.

This is perfectly normal and safe. Lutron dimmers are designed
to the strictest UL safety standard, and can handle their full rated load (a
600 Watt dimmer can handle a full 600W of power*. Without overheating.

*Dimmers that are ganged together in a common wallbox may need to be
derated. Consult the product instruction sheet or call the toll-free Lutron
Hotline 24/7 at (800) 523-9466 for more information about ganging and derating.

WHY
DO I HAVE TROUBLE DIMMING MY PHILLIPS MASTERLINE™
LAMPS ?
These lamps contain a diode which may interfere with proper dimming
performance. Lutron Electronics does not recommend dimming these lamps. Dioded
lamps possess either negative or positive polarity, however, the lamps are not
marked to indicate whether they are positive or negative. Unsatisfactory
dimming performance can occur if the dioded lamps in a circuit have the same
polarity (i.e., all positive or all negative). Under these conditions, the
lamps will flicker and will not dim below approximately 50%. We recommend that
you try one of the following suggestions:

Replace one lamp in the circuit with a lamp of opposite polarity. As long as
there least one positive lamp and one negative lamp in the circuit, no problems
will occur. Since the lamps are not marked as to their polarity, some trial and
error may be required to find a combination of lamps that works properly.

Use a dimmer with neutral connection, such as our Nova®
low voltage series (NLV-600, NLV-1000, NLV-1500). The neutral connection allows
the dioded lamps to dim normally. This solution is also suggested for circuits
with only one dioded lamp.

The Phillips trade name for this bulb is Masterline™.
Phillips has plans to remove the diodes in the near future.

WHY DOES MY LAMP BUZZ ?
Occasionally, you may sometimes notice that a lamp is buzzing. This is
caused by the lamp filament vibrating as the dimmer rapidly switches the lamp
on and off. Lamp buzz is generally noisiest at the mid-range (50%) dimming
level. If this happens, use rough service lamps (sometimes called garage
door opener lamps), physically smaller lamps, or lower wattage lamps.

The most effective way of reducing lamp buzz is to install a lamp debuzzing
coil (LDC) in the lighting circuit. When an LDC is wired in series with the
dimmer, it slows down the inrush of current during the rapid switching cycle of
the dimmer. As the current inrush is slowed down, the lamp filament vibration
and lamp buzz are reduced.

Lutron has two LDC models available to help reduce lamp buzz. The type of LDC
required depends on the total wattage of the dimmer's lighting load. Listed
below are the model numbers and their respective capacities.

LDCs may be wired in series with the dimmer on its line side or load side.
Each dimmer requires its own LDC.

LDCs themselves make an audible buzz, and therefore, should be mounted in an
area where the noise will not be objectionable (e.g. an electrical closet, a
basement, or above a drop ceiling.) The LDCs are UL listed and thermally
protected. For further information, contact the Lutron Hotline and ask for
Application Note #3.

WHY
DO MY LIGHTS FLASH OR SUDDENLY CHANGE LEVELS ?
You may be experiencing a common neutral interaction. Common neutral
interaction is cross talk between dimmers that share the same neutral wire.
This may cause the lights to flicker, flash or suddenly change intensity. When
solid-state dimmers are operating, voltage spikes occur and are transmitted
onto the neutral wire. Normally this is of little concern, except when the
neutral wire is common to two or more phases of a 120/208V, 3-phase, 4-wire
system. Under this condition, the voltage spikes may feed back to the dimmers
via the common neutral wire, causing interacting between the dimmers.

Recommendations:
Lutron recommends the following methods to avoid common neutral interaction:

A.

Separate neutrals

B.

Filter choke

C.

Special Lutron dimmers

Filter ChokesIf it is not possible to run separate neutrals for each phase (e.g. an
application with existing wiring), you can use filter chokes to "clean up" the
voltage spikes creating the interaction. One filter choke is required for each
dimmer. The filter choke makes an audible buzz, so care should be taken to
mount it in an area where the noise will not be objectionable.
Filter chokes can be wired in series on either the line side or the load side
of the dimmer.

Special DimmersIf it is not possible to run separate neutrals or use filter chokes to
correct the interaction, the following special dimmers are available from
Lutron to accommodate common neutral applications:

Model#

Max. Load Capacity

NCN-600

600W

NCN-1000

1000W

NCN-1500

1500W

NCN-2000

2000W

Note: All models are for incandescent lighting
and are available in Nova® style only.

WHAT
IS RADIO FREQUENCY INTERFERENCE (RFI)?
RFI is a buzzing noise which may occur in some audio and radio equipment when
solid-state dimmers are used nearby. Although every Lutron dimmer contains a
filter to suppress RFI, additional filtering may be required in some
applications. Typical examples of RFI-sensitive equipment are AM radios, stereo
sound systems, broadcasting equipment, intercom systems, public address
systems, and wireless telephones.

RFI can be transmitted in two ways:

Radiated

Conducted

Note: The suggestions in this application note
will help minimize RFI: however, they do not guarantee that RFI will be
completely eliminated.

Radiated RFIAny sensitive equipment that is in close proximity to dimming equipment can
pick up the RFI and generate noise into its system.

The following are three possible ways to minimize the radiated RFI:

Physically separate the RFI-sensitive equipment from the dimmer and its wiring.

Run dimmer wiring in its own metal conduit.

Use a lamp debuzzing coil (available from Lutron) to filter the RFI. See below
for more information.

Conducted RFIIn some cases, RFI is conducted through the building wiring and directly
into the AC power supply of the sensitive equipment.

To minimize the conducted RFI, follow these guidelines:

Feed sensitive equipment from a circuit without a dimmer on it.

Add a power-line filter to the sensitive equipment.

Add shielded wire for all microphones and input cables. Also, use low-impedance
balanced microphone cables, which are less susceptible to interference than
high-impedance types.

Make sure all the equipment is grounded. Connect all shields to the ground at
one point. Ground lighting fixture metal housings properly.

Use a lamp debuzzing coil (available from Lutron) to filter the RFI.

Lamp Debuzzing CoilsLamp debuzzing coils (LDCs) are the most effective way to reduce RFI. One
LDC is required for each dimmer. Select the LDC according to the connected
lighting load. The LDCs may be wired in series on either the line side or the
load side of the dimmer. For maximum RFI suppression, keep the wiring between
the LDC and the dimmer as short as possible.

Since the LDC itself make an audible buzz, mount in a location where the noise
will not be objectionable (e.g., an electrical closet, a basement, or above a
drop ceiling). LDCs are designed to easily mount onto a standard 4"x4" junction
box. They are UL listed and thermally protected.

The following LDCs are available from Lutron:

Model #

Rated Capacity:

LDC-10-TCP

600-1200W

LDC-16-TCP

1201-1920W

Note: For more details on LDCs, contact the
Lutron Hotline and ask for Application Note #3.

HOW
CAN I MINIMIZE RADIO FREQUENCY INTERFERENCE?
Radio Frequency Interference (RFI) occurs when solid-state dimmers emit noise
that interferes with AM radios, audio equipment, etc. Every Lutron dimmer
includes radio frequency interference suppression circuitry. Additional
filtering may be required in some applications. In instances where interference
does occur, Lutron recommends the following:

Ensure there is 6' (2m) between the dimmer and audio equipment

Place the dimmer on a separate circuit than the audio equipment

Run dimmer wiring in its own metal conduit

Use a lamp debuzzing coil to filter the RFI

Purchase an in-line filter for the audio equipment

Use an electronic low-voltage dimmer (requires a separate neutral wire) for
incandescent loads.

WILL
LUTRON DIMMERS AFFECT HIGH-END OUTPUT?
When the Lutron dimmer is set at full, most users will not notice a difference
from a switched light. A light meter will register a slightly lower high-end
output, as Lutron dimmers automatically save electricity and make incandescent
bulbs last longer.

The best way to determine transformer type is to contact the manufacturer.

A hint of the transformer construction can often be found in the transformer's
weight
Magnetic (core and coil, toroidal) transformers are often heavy for their size.
Electronic (solid-state) transformers tend to be smaller and are often light
for their size.

WHAT
IS COMMON NEUTRAL INTERACTION?
Common neutral interaction occurs between at least two dimmers that share the
same neutral wire. When solid-state dimmers are operating, voltage spikes occur
and are transmitted onto the neutral wire. Normally this is of little concern.

When the neutral wire is common (to two or more phases of a 3-phase, 4-wire
system) the voltage spikes may feed back to the dimmers. The common neutral
wire can cause interaction between the dimmers that are on different phases.

Following are symptoms of common neutral interaction:

Lights flicker at certain dimmer settings

Lights flash to full output at certain dimmer settings

Light level of a dimmer on one phase inadvertently changes when a dimmer on
another phase is adjusted

Lutron recommends the following methods to avoid common neutral interaction:

Run separate neutral wires for each dimming circuit, from each dimmer's load to
the distribution panel

Multi-location dimmers do use standard 3-way wiring, but make use of one wire
for communications while the other carries the load current. A 3-way switch is
not compatible with this.

WHAT
IS A FASS™?
All Lutron dimmers have an air-gap off. Typically this is integrated into a
slider or paddle switch. Some dimmers have electronics that stay active when
the lights are off, such as an infrared receiver. For these products, the air
gap is activated by a separate Front Accessible Service Switch (FASS). When
open, the FASS completely disconnects the power to the load. This ensures that
there is no leakage current to the fixture during routine lamp maintenance. In
addition, when the FASS is open, no remote locations (3-way, etc.) can
re-energize the circuit.

THERE
IS NO GROUND WIRE IN THE BOX, WHAT DO I DO WITH THE GREEN WIRE?
When no grounding means exists within the wallbox, the 2002 NEC article 404.9
exception to (b) permits a dimmer without a ground connection to be installed
as a replacement. For this type of installation, cap or remove the dimmer
ground wire. A dimmer installed under this exception must be provided with a
plastic, noncombustible wallplate (all Lutron plastic wallplates meet these
requirements).

WHY
ARE SOME DIMMER WIRES NOT COPPER COLORED?
Lutron uses tinned copper wires on some of our products. These wires are silver
in color as a result of the tinning process. Tinned copper wires are compatible
with copper wiring and wire nuts. Lutron uses tinned copper wires to avoid
stray strands and to make our products easier to install.

How
do I eliminate buzz with a magnetic low voltage fixture?
If the fixture has a toroidal type transformer (looks like a donut with wires
wrapped around it) use a dimmer with a neutral wire such as NLV-600.
If your fixture has a "core and coil" transformer (square and heavy) use a lamp
debuzzing coil.

Can
I dim a 4 way circuit?
Yes, a 3 way dimmer will replace one of the 3 way switches. A 4 way circuit can
be dimmed from all switch locations by using a Multi-Location dimmer and 2
Accessory Dimmers such as Maestro, Spacer, Spacer System or Faedra.

Why
are my energy saving or screw in fluorescent lamps dropping out at low end or
flickering?
These lamps, whether they be termed energy saving or otherwise are really
fluorescent lamps at their heart. Even the ones marked or packaged as dimmable
generally exhibit problems with light levels dropping off suddenly when dimming
down or there can be flickering throughout the dimming range. Lutron does not
recommend using these bulbs and reminds you that you are already saving energy
when dimming your regular incandescent lights.